Disease relevance of nodA

• Comparison of the R. meliloti nodA, B, C nucleotide and amino acid sequences with those from R. leguminosarum, as reported in the accompanying paper, shows 69-72% homology, clearly demonstrating the high degree of conservation of common nod genes in these Rhizobium species [1].
• The nitrogen-fixing rhizobia on M. laciniata differed markedly from the other S. meliloti or Sinorhizobium medicae isolates and references in their symbiotic traits such as nifDK RFLP diversity, nodA sequences and nitrogen effectiveness with tree other different annual Medicago species (M. truncatula, M. polymorpha and M. sauvagei) [2].
• This permitted the immunological demonstration that the 21-kDa protein is present in wild-type cells and in nodB- or nodC-defective strains, but is absent from nodA::Tn5 mutants, which confirms that the product expressed in E. coli is identical to that produced by R. meliloti nodA [3].

High impact information on nodA

• Nodule initiation signals were not involved, since LMW succinoglycan from R. meliloti nodD1D2D3 and nodA mutants and from luteolin-induced wild-type cultures elicited effects similar to LMW succinoglycan from the uninduced wild-type strain [4].
• We constructed R. meliloti derivatives having a non-polar deletion of nodA, and carrying a plasmid with either the R. meliloti or the R. tropici nodA gene [5].
• The strain with the R. tropici nodA gene produced Nod factors acylated by vaccenic acid, instead of the C16 unsaturated or hydroxylated fatty acids characteristic of R. meliloti Nod factors, and infected and nodulated alfalfa with a significant delay [5].
• This sequence is also present upstream of common nodA and species specific nodF genes of other Rhizobium species [6].
• The sequence data indicate a large open reading frame with opposite polarity to nodA, -B and -C, coding for a protein of 308 (or 311) amino acid residues [7].

Biological context of nodA

• Sequence analysis of the PCR-amplified nodA gene indicated that seven strains representing different 16S and 23S ribosomal DNA genotypes had identical nodA sequences [8].

Anatomical context of nodA

• Activation of the nodA promoter by the nodD genes of Rhizobium galegae induced by synthetic flavonoids or Galega orientalis root exudate [9].

Analytical, diagnostic and therapeutic context of nodA

• No polymorphism was found in the size of PCR products, suggesting that the separation of nodA from nodBC is a common feature of A. sinicus rhizobia [8].
• The common nod genes, nodD, nodA, and nodBC, were identified by heterologous hybridization and sequence analysis [8].

References